The Vulcan database was a collection of information on all civilizations, astral bodies and spatial phenomena encountered by the Vulcans through the mid-22nd century. The Vulcan star charts made up part of this database.
In 2151, Lieutenant Malcolm Reed checked the Vulcan database for any sightings of a large comet with no result, leading the crew of Enterprise NX-01 to the result they've discovered "Archer's Comet". (ENT: "Breaking the Ice")
Captain Jonathan Archer often allowed himself to be inspired by the Vulcan database as to what planet Enterprise would visit next. Among those planets were the planet housing the monastery at P'Jem and Coridan. During a disastrous first contact with the Andorians, Hoshi Sato studied the database about them, and learned they were "blue skinned" and "militaristic." (ENT: "The Andorian Incident", "Shadows of P'Jem") The Enterprise crew was also able to research amenities on Risa from the database. (ENT: "Fallen Hero")
The database helped the crew to identify a Klingon Raptor-class scout ship discovered in the atmosphere of a class 9 gas giant. Captain Archer later consulted it to learn more about Klingon psychology; it contained over 900 pages on Klingon culture. (ENT: "Sleeping Dogs")
In September 2152, Captain Archer accessed the Vulcan database to find more information about the Vulcan starship mentioned by T'Pol in a previous conversation. He found evidence T'Pol did not mention regarding the complete desctruction of the T'Plana when engaging a class 5 neutronic storm in the 2050s. (ENT: "The Catwalk")
In 2153, in order to avoid talking about the death of his friend and colleague A.G. Robinson with T'Pol, Archer speculated that there might be a paragraph about him in the Vulcan database. (ENT: "First Flight")
USS Voyager had a Vulcan database of their own. In 2372, Neelix consulted it during a study of Vulcan music to find a song that might be considered "cheerful". The song he chose, beginning with the line, "Oh starless night of boundless black," was in fact a traditional Vulcan funeral dirge. (VOY: "Tuvix")